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US ballast water discharges to grow as LNG exports boom

Thu 05 Jan 2017 by Paul Gunton

US ballast water discharges to grow as LNG exports boom
Changes in LNG trades will have a big effect on ballast water discharges in US waters (credit: SERC)

Growing LNG exports from the US could “drive a massive increase in ballast water flux to the US” resulting in “large effects on transfer of non-native organisms,” according to researchers at the Smithsonian Environmental Research Center (SERC).

In a paper to be published soon in the journal Science of the Total Environment, they explore how the shift from the US being a net LNG importer to being a net exporter “will create a surge in ballast water discharge.”

As well as an increase in vessel movements, the switch from LNG importing to exporting means that vessels will arrive empty and thus each carry more ballast than previously. The paper’s authors single out as a highlight of their findings that the “direction and magnitude [of this] change of ballast water flux poses new bio-invasion risks.”

The paper concludes: “While this linkage between energy markets and biological invasions is largely unexplored, understanding how invasion risk is coupled with trade dynamics of specific commodities is crucial to developing successful management strategies.”

Its analysis was prepared during 2016 using data from a wide range of datasets with information up to 2015. The paper includes a forecast that, by 2040, there will be a 90-fold annual increase in LNG-related ballast water discharge to the US compared with 2015 “with the potential to be even greater under high oil prices.”

These effects are not limited to the LNG trades: one of the paper’s references recorded that, in Australia, export of coal and iron ore by bulk carriers doubled the amount of ballast water discharged between 1999 to 2012.

Dr Kimberly Holzer, an aquatic ecologist at the SERC’s Marine Invasions Research Laboratory, is the paper’s lead author. She told BWTT that similar work could be done in other LNG-exporting regions and for other trades. “We are very interested in pursuing global projects on linkages between maritime trade and ballast water-related bio-invasion risks,” she said. Tanker and bulk trades, for example, would “fit into this scheme because these vessel types carry large volumes of ballast water.”

Pre-publication copies of the report can be ordered online at ScienceDirect.